body,
html {
  height: 100%;
}

body {
  padding-top: 50px;
  background-size: 100%;
}

#myBtn {
  display: none;
  position: fixed;
  bottom: 20px;
  right: 30px;
  z-index: 99;
  border: none;
  outline: none;
  background-color: green;
  color: white;
  cursor: pointer;
  padding: 15px;
  border-radius: 10px;
}

#myBtn:hover {
  background-color: darkgreen;
  color: white;
}

.bg-4 {
  background-color: #2f2f2f;
  color: #ffffff;
}

footer {
  display: block;
}

.edit {
  text-shadow: 2px 2px 5px lightgreen;
  color: green;
}